Method of fitting golfer with putter and improving putting accuracy

ABSTRACT

An individual&#39;&#39;s sighting error may be measured when he is adjacent a point and sights a target with the plane formed by the front of his body being substantially parallel to a line between the point and where the target appears to be. A sight line is rotated about the point until it appears that the sight line is pointed directly at the target. The sighting error is detected as an angle between a true line and a projected extension of the sight line and as a directional deviation to the left or right of the true line by the sight line extension. A golf club is provided to compensate for that individual&#39;&#39;s sighting error. The golf club provided includes a correction line which is sloped relative to the striking face of the club at an angle equal to the individual&#39;&#39;s sighting error angle. In using the club, the golfer lines up the correction line normal to his front body plane.

United States Patent [191 Elkins, Jr.

[111 3,826,495 July 30, 1974 METHOD OF FITTING GOLFER WITH PUTTER ANDIMPROVING PUTTING ACCURACY [76] Inventor: Vance V. Elkins, Jr., 42Hampton Dr., Freehold, NJ. 07728 [22] Filed: Mar. 26, 1973 [21] Appl.No.: 344,585

Related U.S. Application Data [62] Division of Ser. No. 156,904, June25, 1971, Pat. No.

[57] ABSTRACT An individuals sighting error may be measured when he isadjacent a point and sights a target with the plane formed by the frontof his body being substantially parallel to a line between the point andwhere the target appears to be. A sight line is rotated about the pointuntil it appears that the sight line is pointed directly at the target.The sighting error is detected as an angle between a true line and aprojected extension of the sight line and as a directional deviation tothe left or right of the true line by the sight line extension.

A golf club is provided to compensate for that individuals sightingerror. The golf club provided includes a correction line which is slopedrelative to the striking face of the club at an angle equal to theindividuals sighting error angle. In using the club, the golfer lines upthe correction line normal to his from body plane.

10 Claims, 6 Drawing Figures METHOD OF FITTING GOLFER WITH PUTTER ANDIMPROVING PUTTING ACCURACY This application is a division of parentapplication Ser. No. 156,904, filed June 25, 1971, now U.S. Pat. No.3,680,860.

Continuity between this divisional application Ser. No. 344,585, filedMar. 26, 1973 and said parent application was maintained by a divisionalapplication, Ser. No. 223,102, filed Feb. 3, 1972, now abandoned.

BACKGROUND OF THE INVENTION 1. Field of the Invention This inventionrelates to the field of art of measuring an individuals sighting errorand to golf clubs for compensating for such sighting error.

2. Prior Art Putters and other golf clubs have been known in the priorart to have alignment lines or other sighting marks. These alignmentlines have generally been provided for the purpose of aiding the golferin visualizing what was considered to be a proper straight line pathfrom the ball to the cup or target hole. The golfer was instructed toview the alignment line and then draw an imaginary extension from thatalignment line through the center of the ball to the target. He wouldthen attempt to hit the ball with a true linear stroke exactly in thedirection of the alignment line toward the target.

In using prior alignment lines with a sloped putting green, the golfermay select a point to one side of the hole and then by viewing thealignment line, the golfer attempts to putt toward that point. The slopeof the green should then cause the ball to follow a curved path awayfrom the point and into the target hole.

Other sighting marks have also been used for another purpose which is toindicate a proper position or spot on the club face to hit the ball.When the ball is hit at this spot on the club face the best possiblestroke has been made for a sweet spot hit.

Prior alignment lines have left much to be desired in that when a golferin an address stance used the line to indicate a true line from ball totarget, he would in reality be following an incorrect line. What was notknown and taken into account was the personal and inherent sightingerror where each individual has his own sighting error. Individuals seethings differently than they actually are when addressing a ball. Forexample, a right handed golfer may see the target at a particularangular sighting error to the right of where it actually is. Thus, prioralignment lines made no correction for an individuals sighting error.

Not only did prior alignment lines not aid the individual golfer, butthey had the harmful effect in directing golfers to swing along anincorrect path. The golfer learns by practicing that in order to reachthe target while following the alignment line, he must build insubconscious and subtle corrective movements from a true linear stroke.In this way, he subconsciously corrects for his unperceived sighting eyeerror.

l-Iis corrective movements may comprise one or more of the following. Hemay swing across the ball pulling it or pushing it back to where thetarget actually is in order to put the ball in the cup. Anothersubconscious corrective movement may be to rotate the club head in thecourse of the stroke from an open to a closed position. Thesesubconscious corrective movements from the true linear stroke are verycomplex and have been found in practice to be extremely hard toreproduce.

This difficulty in reproducibility may be seen, for example, in thateven professional golfers miss 45 percent of their 6 foot putts althoughonly 10 percent of these missed putts can be attributed to randomness ofthe green or incorrect distance judgment as set forth in a text byCochran and Stobles, The Search for the Perfect Swing. Golf Society ofGreat Britain, 1968, pp. 137 and 189, Tables 21:2 and 29:4.

This text describes experiments with a perfect putting machine onaverage putting greens. It has been experimentally found that even witha perfect machine, as the putting distance increases, there is a higherpercentage of putts missed as a result of the randomness of the puttingsurfaces. The level of skills of professional and amateur golfers isgiven in the text.

There is a substantial difference between the skills of golfers and theperfect putting machine and these differences are attributed to basicproblems of the golfer. In the longer putts, the errors are equallyattributable to errors in direction and errors in distance measurement.However, in shorter putts, such as 10 feet or less, errors in distanceare negligible with the major error being caused by error in alignmentand/or direction of stroke. The foregoing is seen in the following tablewhich is a combined and simplified form of the above cited Tables in thetext.

% Missed Because of:

It will be understood from the above that golfers miss a high percentageof short putts since they are effectively unable to coordinate theirsighting and stroke. Thus, with any of the prior putters, even theprofessional golfer is unable to putt consistently and accurately.

SUMMARY OF THE INVENTION An individuals sighting error is measured byfirst rotating a sight line about a point until to the individuals view,it appears that the sight line is pointed directly at the target. Thesighting error is then detected (a) as an angle between (i) a true lineformed between the point and the target and (ii) a projected extensionof the sight line. This error corresponds to a directional deviation tothe left or right of the true line by the sight line extension.

Further, a golf club is provided having an error correction line with aforward extension which forms with respect to a line normal to the clubface an angle and directional deviation corresponding to the sightingerror angle and directional deviation respectively.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates in simplified forma top view of a system and method for measuring an individual s sightingerror according to the invention;

FIG. 2 illustrates in simplified fortn a top view of another embodimentof the sighting error measuringsystem and method according to theinvention;

FIG. 3 illustrates a top view of a putter which is provided tocompensate for the individuals sighting error in FIG. 1;

FIG. 4 illustrates in more detail a perspective view of the putter ofFIG. 3 with a different correction line;

FIG. 5 is a top view of a putter showing a further embodiment of theinvention; and,

FIG. 6 illustrates a top view of a putter which is provided tocompensate for an individuals sighting error in accordance with theinvention.

Referring now to FIG. 1, there is shown the manner in which the sightingerror of an individual may be measured. While the measuring system andmethod shown in FIG. 1 is directed to golfers, it will be understoodthat this system and method may be used for measuring sighting errors asdefined herein, for any prupose. An individual 10 assumes his usual andnormal golf ball putting address stance as shown in which he attempts toalign himself in front of a point 16 representing a golf ball. Theindividual golfer views a target 11, which for example, may be a lightobject in a dark background. Target 11 may be about the size of a golfball so that it appears to the golfer as a point target. In a typicalexample, target 11 may be approximately feet from point 16; indicated inFIG. 1 as distance B. i

The individual in assuming the usual and normal address stance lineshimself up square with his feet and body. It is then important that theindividual have his head and eyes in the position he would normally useto judge his line of sight to target 11. He places his arms behind hisback to eliminate any corrections he may make by swinging his arms in apractice stroke. It is helpful to eliminate this feelT to obtainaccurate measurement of the sighting error.

Point 16 is at the axis of a dark heavy sight line 12 on a circular disc15 which is rotated by a reversible motor 14. Push button switches and21 may be provided respectively under the left and right foot of golferl0. Actuation of switch 20 causes a slow clockwise rotation of disc 15while actuation of switch 21 causes a slow counterclockwise rotation ofdisc 15.

As shown in FIG. 1, a true line 28 extends as a striaight line betweenpoint 16 and target 11. From his normal stance, golfer 10 visuallysights along sight line 12 to target 11. Golfer 10 actuates switches 20and 21 until he believes sight line 12 is pointed at and is aligned withtarget 11. The actual position of line 12 in a typical example is shownin FIG. 1. Sight line extension 24 is the imaginary projected extensionof line 12 and forms with true line 28 a sighting error angle 34 to theright of line 28. It will now be understood that individual 10 bysquaring himself has assumed an address stance in which the plane formedby the front of his body is substantially parallel to line 24.

In order to automatically measure the sighting error as a slight angleand as a directional deviation to the left or right of true line 28, acollimated light source 25 is then energized. Source 25 directs a beamof collimated light over target 11, along line 28 and over point 16 to amirror 27. Mirror 27 is mounted on a support 27a secured to disc 15 asshown with the reflecting surface of the mirror being normal to sightline 12.

The collimated light is reflected along line 26 and Chart 30 is directlybehind source 25. Reflected line 26 is not coincident with sight lineextension 24 for the following reasons. The light from source 25 isreflected by mirror 27 to form line 26 at an angle 35 with the true line28 equal to the sum of the angle of incidence and the angle ofreflection which is approximately equal to twice the value of angle 34.Therefore, chart 30 which is normal to line 28 is scaled accordingly.With the sighting error being measured for golfer 10, he may now beprovided with a club 100 having a 2R (2 to the right of line 28)sighting error correction line or stripelike indicia 105 as will laterbe described in detail.

In an example, the elements may have the following values:

' Disc 15 1 foot diameter Mirror 27 1 inch square Light beam 25a 2 inchdiameter Thus, it will be understood that FIG. 1 is out of proportionwith the actual values of angles 34, 35, mirror 27, distance B, etc. andhas been drawn in this way solely for the purpose of simplifyingexplanation.

In another embodiment golfer 10a stands before an irregular shaped pieceof cardboard 40 on which is drawn a sight line 41 and visually sightsfrom a point 42 on sight line 41 to a target 43. True line 38 extendsbetween 42 and 43. Board 40 is rotated or moved about point 42preferably by another person until the individuals visual observation,it appears that the sight line extension 44 is pointed directly attarget 43.

In order to calculate the sighting error a chart 52 is laid normal totrue line 39. A string is stretched from point 50 (to take advantage ofthe entire length of line 41) along sight line 41 and extension 44 untilit crosses chart 52 at point 54. Sighting error angle 47 is calculatedby using the formula of the tangent of the angle is equal to distance-Aas shown divided by distance B. It will be understood that for ease incalculation charts may be made using as a basis a fixed distance andplotting a scale on chart 52.

It will be understood that several measurements of golfer 10 may be madeand the statistical average of his sighting error calculated. The reasonfor such a statistical average is that individuals vary in their testingconsistency. Some individuals are very consistent while others givevariable measurements over several tests. In some cases of nonconsistentmeasurements, it is helpful to cover the nondominant eye of theindividual while taking the measurements. Such individuals may have avariable ability to fuse. Thus, by closing the nondominant eye, theindividual no longer has to fuse his two eyes together to scan line 41.

Referring now to FIG. 3, there is shown a golf club 100, which in thisembodiment is a golf putter, having a sighting error correctionstripe-like indicia or line 105. Correction line 105, visible to golfer10b in his ball address stance, corrects for a 2R sighting error asshown in FIG. 1. This 2R sighting error is indicated by indicia notation108 located on the bottom face of the forms a shining spot on chart 30at indication 2R.

club. Line passes through the geometrical center 105a of club 100.Imaginary line 109 is normal to club face 110, also passes throughcenter 105a and forms an angle 102 with line equal to sighting errorangle 34, FIG. 1.

As shown, the projected extension of line 109 is true line 112. To theright of true line 112, extension line 106 is formed as the projectedimaginary extension of correction line 105. In this manner, there isformed a 2R sighting error correction which is personal to individualgolfer 10.

Parallel to imaginary line 109 and perpendicular to club face 110 areedge lines 115-116 with the stripe or band area 120 between these linesbeing finished in a contrasting color to the remaining top visible faceor upper surface of club 100. Line 105 is preferably finished in acontrasting dark color with respect to area 120 so that line 105 ishighly visible.

Golfer assumes a golf stance next to golf ball 122 and positions club100 so that line 105 and its extension 106 appear to him to be pointeddirectly at an actual target hole 135. For the reasons previouslydescribed, lines 105 and 106 will actually be pointed at a visualizedtarget hole 136. Thus, golfer 10 has squared himself with lines 105 and106 and band 120 is now pointed directly at the actual hole 135 withlines 115-116 being parallel to true line 112. Further, club face 110 isaimed directly at the actual target hole 135, i.e., face 110 is normalto true line 112.

The golfer now focuses himself only on the problem of stroking ball 122and no longer concerns himself with the problem of positioning club 100.Golfer 10 concentrates on preventing rotation of band 120 (and therebyline 105) during his back and forward stroke and in this manner, heinsures ball 122 being hit and moving along true line 122 directly intotarget hole 135.

With the provision of an individuals sighting error correction line 105,similar to sight line 12 of FIG. 1, golfer 10 can consistently andreproducibly aim club face 110 directly at hole 135. It will be notedthat golfer 10 is not actually square with club face 110. However, agrip 120 on shaft 107 has a flat portion 122 parallel to band 120 sothat the golfer properly grips the club to assist him in stroking alongtrue line 112.

Referring now to FIG. 4, in a specific example, club 100 may havecorrection line 1051) formed as a 3/32 inch thick line on upper face 125and extending from front face 110 to the back edge 126 of putter 100, asshown. In FIG. 4, line 105b provides a correction 1R (1 to the right oftrue line) as indicated by notation 108a on the end of handle 120'. Band120 may be 1.68 inch (the diameter of a standard American golf ball)wide white band on top face 125 with the stripe extending from frontface 110 to the club back edge 126, a distance of approximately 3inches. White band 120 contiasts with the dark color of the remainingportion of top face 125 so that the edge lines 115-116 are readily seen.

Club 100 may itself be used as a means for the golfer to calibrate hiseyes and check his sighting error. The player first assumes the balladdress stance. He then points line 105 at where he believes the targetis by rotating the club. In this way, line 105 is effectively rotatedapproximately about a point defined by center 105a. The golfer holdsputter 100 in place on the ground and then moves behind the club to viewband 120. Band 120 and its lines 115-116 should be aimed directly attarget 135 assuming that his sighting error has not changed. If thewhite band 120 is not pointed directly at target 135, the golfer maytake into account the small eye variation in the angular sighting errorfor that day by adjusting his reading of the putt. In this manner, thereis provided a self-calibration procedure for the golfer.

It has been found that while any one individual s sighting error isbasically a constant value, there may be a variation about that personalsighting error plus or minus /2. Accordingly, a serious player or aprofessional may prior to a round of golf determine his sighting erroron that day and select for that day a putter from a matched set whichcovers his range of sighting error.

In professional golf, it is permissible under the rules for a caddy toassist a golfer in lining up club for a putt. Accordingly, the caddy canview stripe 120 from behind the player and tell him if lines 115-l 16are lined up with true line 112. If not, the caddy may then suggest thatthe putter be turned to precisely aim at the desired direction.

The clubs themselves may be used to determine the proper sighting errorcorrection line for an individual. A golfer is first given a club thathas a zero degree sighting error correction line and is told to pointthat line directly at the target. The person fitting the club standsbehind the player with the plane formed by the front of his body normalto true line 112 and views band 120.

If band 120 is pointed to the right then an R correction is requiredwith the fitter estimating the proper number of degrees for the sightingerror angle. A putter is provided with that error correction and thegolfer lines up the new club in the manner previously described. If thefitter views band 120 as pointed directly at the target, a proper putterhas been selected.

On the other hand, if band 120 is pointed to the right of the target,then a higher valued angle is required. If band 120 is pointed to theleft of the target, then a lower valued angle is required. The golfer isthen given a club with the new estimated value of angle and theforegoing process is continued until band 120 is pointed at the targetto the satisfaction of the fitter.

Referring now to FIG. 5, there is shown a still further embodiment inwhich putter 100a has a correction line l05b similar to the correctionlines in FIGS. 34. However, in FIG. 5, the edge lines l15a-l 16a of band120a are no longer normal to club face but form an angle therewith equalto the angle formed by line 105b. In this manner, all three lines, 105b,115a and 116a are parallel to each other and all provide sighting errorcorrection. However, band 120a can no longer be used for fitting orcalibrating the putter 100a in the manner previously described.

While the golf clubs 100 and 100a in FIGS. 3-5 are all shown as putters,it will be understood that other golf clubs may have the sighting errorcorrection line as well as the band. However, for the correction line tobe used on the top face, there must be a sufficient distance between theclubs front face and back edge to allow the golfer to view and sightalong the correction line. Accordingly, woods generally provide a topface which would incorporate a sufficiently long correction line.

It will be understood that correction lines 105, 105b may be formedother than on the top face of the club. What is important is that thecorrection line be visible to the individual when holding the club inthe address stance.

Band 120 and line 105 are preferably formed and colored on club 100 inthe manufacturing process. However, bands having correction lines ofdiffering angles and directional deviations may be supplied as tapeswith press contact adhesives. Thus, a tape would be applied to a clubproviding the proper error correction for an individual.

A still further embodiment of the invention is shown in FIG. 6 in whichputter 1001) is shown having an alternate correction stripe-like indiciaor line 150 in addition to correction line 105. Correction line 150 isdrawn normal to the correction line 105 and extension line 106, FIG. 3.As in FIG. 3, band 156 and edge lines 157-158 are normal to club frontface 152.

The purpose of line 150 is as follows. It is customary for many golfersto line up face 152 normal to their front body. By lining up correctionline 150 normal to his front body plane, band 156 will thus be aimeddirectly at the actual target along true line 112.

In operation, golfer 10 lines up correction line 150 normal to his frontbody plane and in this way, has squared himself with lines 105 and 106.The golfer now focuses himself only on the problem of stroking the ballin the manner described with respect to FIG. 3. Golfer 10 is to line-uponly correction line 150 normal to his front body plane.

It will be understood that correction line 150 may be used alone withoutline 105. Accordingly, lines 105-106 may both be considered an imaginaryline intersecting and normal to line 150 and appearing to. be

. pointed directly at target 136.

What is claimed is:

l. A method of correcting for an individuals inaccurate aim when puttingand thereby improving said individuals accuracy and consistency inputting a golf ball with a golf putter comprising the sequential stepsof:

1. said individual, while assuming a substantially normal puttingstance, orienting a sight line so that it appears to said individual tobe aimed at a target, which sight line is located upon or adjacent apoint from which a golf ball normally would be putted by said individualwhile in said stance,

2. determining said individuals inherent and personal sighting error asthe angle between an extension of said apparently accurately aimed sightline to a location laterally of said target and a true line extendingbetween said point and said target, and

3. said individual putting a golf ball while assuming said substantiallynormal stance with a putter having correction stripe-like indicia on theputter head while attempting to maintain said correction stripelikeindicia aimed perpendicular to a putting target when positioning theputter head rearwardly of the ball and when striking the ball during theputting stroke, which correction stripe-like indicia is sloped relativeto the striking face of said putter at an angle equal to saidindividuals sighting error angle.

2. The method of claim 1 in which the individual in his normal puttingstance has both feet on the same side of said true line.

3. The method of claim 1 in which said indicia is located between theshaft and the toe of the club head.

4. The method of claim 1 in which said determining step includes (a)detecting a first intersection of said true line with a plane and (b)detecting a second intersection of said sight line extension and saidplane.

5. The method of claim 1 in which said determining step includes (a)detecting a first intersection of said true line with a flat real planeperpendicular to said true line and (b) detecting a second intersectionof said sight line extension and said flat real plane, and observing thedeviation of said second intersection from said first intersection.

6. The method of claim 5 in which said determining step further includesdisposing said target within said real plane.

7. The method of claim 5 in which said determining step furthr includesdisposing said target in front of said real plane.

8. The method of claim 5 in which said flat real plane is in the form ofa chart and said detecting a second intersection step includesdetecting, with respect to markings on said chart, the intersection ofsaid sight line extension and said chart.

9. A method of correcting for an individuals inaccurate aim when puttingand thereby improving said individuals accuracy and consistency inputting a golf ball with a golf putter comprising the sequential stepsperformed by said individual of:

l. orienting, while assuming a substantially normal putting stance, asight line extension so that it appears to said individual to be aimedat a target, which sight line is located upon or adjacent a point fromwhich a golf ball normally would be putted by said individual while insaid stance,

2. observing his or her inherent and personal sighting error as thelateral distance between an extension of said apparently accuratelyaimed sight line and said target, and

3. putting a golf ball while assuming said substantially normal stance,with a putter having correction stripe-like indicia on the putter headwhile attempting to maintain said correction stripe-like indicia aimedperpendicular to a putting target when positioning the putter headrearwardly of the ball and when stroking the ball during the puttingstroke, which correction stripe-like indicia is sloped relative to thestriking face of said putter sufficient to compensate for saidindividuals sighting error.

10. A method of fitting an individual with a golf putter to correct theindividuals inaccurate aim when putting thereby to improve theindividuals accuracy and consistency in putting comprising the steps of:

l. requiring the individual to assume his or her normal putting stance,

2. requiring the individual to orient a sight line so that it appears tothe individual to be aimed at a predetermined distance target, whichsight line is located upon or adjacent a point from which a golf ballwould normally be putted while the individual is in said stance,

3. detecting said individuals sighting error, after the individual hasapparently accurately aimed the sight line, as the angle between anextension of. said sight line to a location laterally of said target anda true line extending between said point and said target, and

4. providing said individual with a putter having correction stripe-likeindicia on the putter head which is sloped relative to the striking faceof said putter at an angle equal to said individuals sighting errorangle.

1. A method of correcting for an individual''s inaccurate aim whenPutting and thereby improving said individual''s accuracy andconsistency in putting a golf ball with a golf putter comprising thesequential steps of:
 1. said individual, while assuming a substantiallynormal putting stance, orienting a sight line so that it appears to saidindividual to be aimed at a target, which sight line is located upon oradjacent a point from which a golf ball normally would be putted by saidindividual while in said stance,
 2. determining said individual''sinherent and personal sighting error as the angle between an extensionof said apparently accurately aimed sight line to a location laterallyof said target and a true line extending between said point and saidtarget, and
 3. said individual putting a golf ball while assuming saidsubstantially normal stance with a putter having correction stripe-likeindicia on the putter head while attempting to maintain said correctionstripe-like indicia aimed perpendicular to a putting target whenpositioning the putter head rearwardly of the ball and when striking theball during the putting stroke, which correction stripe-like indicia issloped relative to the striking face of said putter at an angle equal tosaid individual''s sighting error angle.
 2. determining saidindividual''s inherent and personal sighting error as the angle betweenan extension of said apparently accurately aimed sight line to alocation laterally of said target and a true line extending between saidpoint and said target, and
 2. observing his or her inherent and personalsighting error as the lateral distance between an extension of saidapparently accurately aimed sight line and said target, and
 2. requiringthe individual to orient a sight line so that it appears to theindividual to be aimed at a predetermined distance target, which sightline is located upon or adjacent a point from which a golf ball wouldnormally be putted while the individual is in said stance,
 2. The methodof claim 1 in which the individual in his normal putting stance has bothfeet on the same side of said true line.
 3. The method of claim 1 inwhich said indicia is located between the shaft and the toe of the clubhead.
 3. detecting said individual''s sighting error, after theindividual has apparently accurately aimed the sight line, as the anglebetween an extension of said sight line to a location laterally of saidtarget and a true line extending between said point and said target, and3. putting a golf ball while assuming said substantially normal stance,with a putter having correction stripe-like indicia on the putter headwhile attempting to maintain said correction stripe-like indicia aimedperpendicular to a putting target when positioning the putter headrearwardly of the ball and when stroking the ball during the puttingstroke, which correction stripe-like indicia is sloped relative to thestriking face of said putter sufficient to compensate for saidindividual''s sighting error.
 3. said individual putting a golf ballwhile assuming said substantially normal stance with a putter havingcorrection stripe-like indicia on the putter head while attempting tomaintain said correction stripe-like indicia aimed perpendicular to aputting target when positioning the putter head rearwardly of the balland when striking the ball during the putting stroke, which correctionstripe-like indicia is sloped relative to the striking face of saidputter at an angle equal to said individual''s sighting error angle. 4.providing said individual with a putter having correction stripe-likeindicia on the putter head which is sloped relative to the striking faceof said putter at an angle equal to said individual''s sighting errorangle.
 4. The method of claim 1 in which said determining step includes(a) detecting a first intersection of said true line with a plane and(b) detecting a second intersection of said sight line extension andsaid plane.
 5. The method of claim 1 in which said determining stepincludes (a) detecting a first intersection of said true line with aflat real plane perpendicular to said true line and (b) detecting asecond intersection of said sight line extension and said flat realplane, and observing the deviation of said second intersection from saidfirst intersection.
 6. The method of claim 5 in which said determiningstep further includes disposing said target within said real plane. 7.The method of claim 5 in which said determining step furthr includesdisposing said target in front of said real plane.
 8. The method ofclaim 5 in which said flat real plane is in the form of a chart and saiddetecting a second intersection step includes detecting, with respect tomarkings on said chart, the intersection of said sight line extensionand said chart.
 9. A method of correcting for an individual''sinaccurate aim when putting and thereby improving said individual''saccuracy and consistency in putting a golf ball with a golf puttercomprising the sequential steps performed by said individual of:
 10. Amethod of fitting an individual with a golf putter to correct theindividual''s inaccurate aim when putting thereby to improve theindividual''s accuracy and consistency in puttIng comprising the stepsof: